JP5191636B2 - Cogeneration system - Google Patents

Description

  The present invention relates to a cogeneration system including a combined heat and power generator that generates electric power and heat and a heat accumulator that stores heat.

  A fuel cell, a means for measuring an electric load (power consumption energy) and a heat load (heat consumption energy due to hot water supply, etc.), and a measuring instrument for predicting these future demands from past load history detected by the measuring instrument, And an operation mode determiner that determines the operation mode of the system based on the future hot water supply demand by the predictor, and can appropriately adjust the amount of hot water in the hot water storage tank so as to appropriately cover the future hot water supply demand Fuel cell cogeneration systems have already been developed.

  For example, a system has been proposed that changes the operation mode of a fuel cell cogeneration system in accordance with a change in hot water supply demand in the next morning due to a difference in the living environment in the season (summer and winter) (see Patent Document 1 as a conventional example) ).

According to this conventional fuel cell cogeneration system, when the demand for hot water supply in the next morning increases (in winter), the hot water storage tank is provided at the end of the hot water demand peak based on the hot water supply demand in the next morning, while supplying hot water for the night of the day. The amount of hot water stored in the hot water storage tank is adjusted so that the amount of hot water stored in the cogeneration system is zero.
JP 2005-9846 A

  Considering the predicted hot water demand in the next morning as in the conventional fuel cell cogeneration system, controlling the operation so that the amount of hot water in the hot water storage tank becomes zero at the end of the peak is to minimize the energy loss of the system. preferable.

  However, the actual hot water supply demand may cause an unexpected demand, and it is difficult in reality to completely predict the hot water supply demand, and there is a high possibility that the predicted value will be excessive or insufficient. If there is a surplus in the actual hot water supply demand, it is necessary to make up for the shortage with a backup burner or the like, leading to a decrease in energy efficiency. Even if prediction becomes possible, there is a concern that the cost of the cogeneration system may increase due to the high performance of the control system.

  The present invention has been made in view of such circumstances, and a cogeneration system that can appropriately cope with a heat load demand caused by unexpected hot water supply or the like without causing an increase in the cost of the control system of the cogeneration system. The purpose is to provide.

  The present inventor has intensively studied the above-mentioned problems, and on the premise that the future hot water supply demand cannot be perfectly predicted, the present inventor has made a code so as to coexist with an operation mode in which an excess amount of hot water can be stored in the hot water storage tank. We focused on the fact that designing the generation system can reduce the burden on the control system.

  In order to solve the above problems, a cogeneration system according to the present invention is provided with a thermoelectric generator that generates electric power and heat, a heat accumulator that stores heat generated by the thermoelectric accumulator, and heat supplied from the heat accumulator. A storage device for storing a predicted heat load demand of the heat load and a predicted recovered heat amount from the cogeneration unit to the heat accumulator; and a controller, the controller acquired from the storage device Based on the predicted heat load demand and the predicted recovered heat amount, the combination of the start time and the stop time at which the amount of heat exceeding the value necessary to cover the predicted heat load demand is stored in the regenerator is scheduled to start It is set as time and scheduled stop time.

  According to the cogeneration system configured as described above, since the heat storage unit stores a larger amount of heat storage than the heat load demand in the daily prediction during standby of the combined heat and power supply, it is temporarily unexpected. Even when a heat load demand occurs, the heat shortage due to the unexpected heat load demand can be compensated to a certain level compared to the heat load exhaustion logic of the regenerator like the conventional cogeneration system. .

  In the cogeneration system of the present invention, the storage unit further stores the predicted power generation amount of the combined heat and power supply device, and the controller is configured to store the predicted thermal load demand acquired from the storage unit. Based on the predicted recovered heat amount and the predicted power generation amount, an amount of heat exceeding a value necessary to cover the predicted heat load demand can be stored in the regenerator, and consumption of the cogeneration unit A combination of the start time and the stop time of the cogeneration unit that maximizes at least one of the energy reduction amount, the cost reduction amount, and the carbon dioxide emission reduction amount is set as the scheduled start time and the scheduled stop time. And

  Further, the cogeneration system of the present invention includes a thermal load measuring instrument that measures a heat consumption history of the thermal load, and the controller detects an unexpected heat load demand by the thermal load measuring instrument. In addition, at least one of the scheduled start time and scheduled stop time may be changed so as to increase the amount of heat stored in the regenerator.

  According to the cogeneration system configured as described above, the controller can grasp the generation of the unexpected heat load demand and the unexpected heat load demand based on the detection information of the heat load measuring device. For this reason, the controller can estimate the insufficient heat quantity by subtracting the heat quantity of the regenerator that covers the daily heat load demand (within the forecast) from the unexpected heat load demand, and can cover the insufficient heat quantity. Thus, it is possible to change the scheduled start time (unarrived time) and / or scheduled stop time (unarrived time) of the combined heat and power supply.

  In the cogeneration system of the present invention, when the controller detects an unexpected heat load demand by the thermal load measuring device, the scheduled start-up time may be advanced by the thermal load measuring device. If an unexpected heat load demand is detected, the scheduled stop time may be delayed.

  Further, the cogeneration system of the present invention is configured to set a substantially maximum heat storage amount in the heat accumulator during standby of the heat and power supply unit based on the predicted heat load demand obtained from the storage device and the predicted recovered heat amount. A combination of the start-up time and stop time of the combined heat and power supply unit that is stored may be set as the start-up scheduled time and the planned stop time.

  The cogeneration system configured as described above can cope with, for example, a night emergency that requires ensuring a sufficient amount of hot water in the hot water storage tank during standby at night.

  In addition, the cogeneration system of the present invention includes a thermoelectric generator that generates electric power and heat, a heat accumulator that stores heat generated by the thermoelectric accumulator, and a thermal load that is supplied with heat from the heat accumulator. A storage device for storing a heat load demand, a predicted recovered heat amount from the cogeneration unit to the regenerator, and a predicted power generation amount of the cogeneration device, and a first operation mode and a second operation mode An operation mode selector for selecting any one of the above, and a controller, wherein the controller obtains the prediction obtained from the storage device when the first operation mode is selected by the operation mode selector. Based on the heat load demand and the predicted recovered heat amount, the combination of the start time and the stop time at which the amount of heat exceeding the value necessary to cover the predicted heat load demand is stored in the regenerator is started. When the second operation mode is selected by the operation mode selector, based on the predicted recovered heat amount and the predicted power generation amount acquired from the storage device, the fixed time and the scheduled stop time are set. A combination of start time and stop time that maximizes at least one of the energy consumption reduction amount, cost reduction amount, and carbon dioxide emission reduction amount of the combined heat and power supply is set as the scheduled start time and the scheduled stop time. To do. An example of the operation mode selector is a remote control switch operated by a user.

  Therefore, the cogeneration system configured as described above is convenient because the user can appropriately select an operation mode suitable for the life cycle by the remote control switch.

  ADVANTAGE OF THE INVENTION According to this invention, the cogeneration system which can cope appropriately with the heat load demand by unexpected hot water supply etc. is obtained, without causing the cost increase of the control system of a cogeneration system.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an example of the configuration of a cogeneration system including a cogeneration system and a heat accumulator according to an embodiment of the present invention, and a fuel cell as an example of the cogeneration system here It is shown.

  As shown in FIG. 1, the cogeneration system 100 of the present embodiment is largely divided into a combined heat and power system 101, a heat (waste heat) utilization system 102, a power system 103, and a control system 104. Separated.

  A cogeneration system 101 of the cogeneration system 100 includes a polymer electrolyte fuel cell 10 (hereinafter referred to as “PEFC10”) that generates power and heat using hydrogen-rich fuel gas (reducing agent gas) and air (oxidant gas). A fuel supply unit 11 that generates a fuel gas from the raw material gas and water and supplies the fuel gas to the anode of the PEFC 10, and an air supply unit 12 such as a blower that supplies air to the cathode of the PEFC 10. It has. The fuel supplier 11 includes, for example, a reformer (not shown) that generates fuel gas by steam reforming a source gas such as city gas 13A, and a transformer (not shown) that transforms the reformed fuel gas. And a selective oxidizer (not shown) that oxidizes the carbon monoxide gas in the fuel gas after the transformation.

  In the PEFC 10, the fuel gas (off gas) that has not been consumed at the anode is discharged from the anode to the outside of the PEFC 10. Further, air that has not been consumed at the cathode is discharged from the cathode to the outside of the PEFC 10.

  In the present embodiment, the PEFC 10 is exemplified as the combined heat and power supply. However, the combined heat and power supply may be another type of fuel cell, and is not limited to the fuel cell, and may be a gas engine method or a gas turbine method. The adopted apparatus may be used.

  The PEFC 10 is configured based on a known technique, and the illustration and description of the internal configuration of the PEFC 10 are omitted here.

  The heat utilization system 102 of the cogeneration system 100 mainly includes an exhaust heat recovery system and a heat storage system.

  As shown in FIG. 1, the exhaust heat recovery system of the heat utilization system 102 is provided in the middle of the cooling water circulation passage 21 a and an annular cooling water circulation passage 21 a formed so as to circulate the cooling water inside the PEFC 10. The heat recovery is performed by flowing the heat recovery water (heat medium) that exchanges heat between the cooling water pump 21b that can circulate the cooling water and the cooling water that flows in the cooling water circulation passage 21a via the heat exchanger 23. A water circulation channel 21c and a heat recovery water pump 21d provided in the middle of the heat recovery water circulation channel 21c and capable of circulating the heat recovery water are provided.

  Although illustration is omitted here, an appropriate temperature sensor for measuring the temperature of the cooling water and the heat recovery water, and the cooling water and the heat recovery water are provided in the middle of the cooling water circulation channel 21a and the heat recovery water circulation channel 21c. An appropriate flow sensor for measuring the flow rate of the water is provided, and the flow rate is appropriately adjusted by the control system 104 described later so that the temperature of the cooling water and the heat recovery water is kept constant based on the detection information of each sensor. ing.

  According to such an exhaust heat recovery system, the flow rate of cooling water and the temperature thereof can be adjusted appropriately, so that the internal temperature of the PEFC 10 can be kept constant.

  In this way, the exhaust heat based on the power generation reaction of the PEFC 10 is appropriately recovered by the cooling water and the heat recovery water based on the heat exchange via the heat exchanger 23, and as a result, the change in the internal temperature of the PEFC 10 is suppressed. Thus, the power generation reaction of PEFC 10 can be kept in a steady state, which is preferable.

  As shown in FIG. 1, the heat storage system of the heat utilization system 102 is connected to the heat recovery water circulation passage 21c and connected to the bottom of the hot water storage tank 22a of the stacked boiling type and the hot water storage tank 22a. A hot water supply pipe 22b leading to 22a, and a hot water supply pipe 22c connected to the upper side of the hot water storage tank 22a for leading hot water from the hot water storage tank 22a to a thermal load (not shown) as a hot water supply facility having a backup burner such as a home bath or kitchen. The flow meter 22d is provided in the middle of the hot water supply pipe 22c and measures the flow rate of hot water flowing through the hot water supply pipe 22c.

  The heat recovery water inlet (the hot water outlet 22e accumulated in the hot water storage tank 22a) of the heat recovery water circulation passage 21c is disposed at the lower end of the hot water storage tank 22a, and the heat recovery water outlet ( The hot water inlet 22f) toward the hot water storage tank 22a is disposed at the upper end of the hot water storage tank 22a, so that the cold water below the hot water storage tank 22a serves as heat recovery water through the heat recovery water inlet. It flows toward the heat exchanger 23 in the water circulation channel 21c. Thereafter, the heat recovery water is heated in the heat exchanger 23, and the heated heat recovery water is returned to the hot water storage tank 22a as a heat storage medium through the heat recovery water outlet.

  Here, the flow meter 22d functions as a thermal load measuring instrument that measures the thermal load of the thermal load as described later. Note that a temperature sensor (not shown) for measuring the hot water temperature may be provided in the middle of the hot water supply pipe 22c, whereby the control system 104 is based on the temperature information of the temperature sensor and the flow rate information of the flow meter 22d. The heat load of the heat load can be detected more accurately.

  According to such a heat storage system, since the heat recovery water flowing through the heat recovery water circulation passage 21c can be heated by the heat exchange action of the heat exchanger 23, the exhaust heat energy released from the PEFC 10 is stored in the hot water storage tank 22a. It can be used at home as thermal energy contained in hot water.

  As shown in FIG. 1, the power system 103 of the cogeneration system 100 includes an inverter 30 that converts the DC power of the PEFC 10 into AC power, and a commercial power supply for supplying AC power supplied from the PEFC 10 to a power load (not shown). In addition to the cogeneration system 100, a commercial power supply 33 of an existing infrastructure by an electric power company is further linked to the electric power load.

  In addition, a power meter 32 capable of monitoring the amount of power used in each home is disposed in the commercial power network 31. The power meter 32 functions as a power load measuring device that measures the power load of the power load as described later.

  The control system 104 of the cogeneration system 100 includes a prediction unit 41, an operation planning unit 42 (controller), a storage unit 40, and a remote controller 43.

  The switch of the remote control 43 of the control system 104 functions as an operation mode selector that switches the operation mode of the cogeneration system 100. As will be described later, the operation modes of the present embodiment include a “maximum energy consumption reduction operation mode” and a “hot water supply mitigation operation mode”.

  The storage unit 40 of the control system 104 stores the power consumption history of the most recent power load of the power load measured by the power meter 32 and the heat of the most recent heat load of the heat load measured by the flow meter 22d. The consumption history is sequentially stored as the cogeneration system 100 operates.

  The control system 104 includes a microprocessor or the like, and has a timer function such as a timer, an arithmetic function, and an internal memory (ROM or RAM). And the memory | storage part 41 is comprised with this internal memory, and the operation | movement of the estimation part 41 and the driving | operation plan part 42 is implement | achieved by the program stored in the memory | storage part 40. FIG.

  The prediction unit 41 reads the heat consumption history of the heat load and the power consumption history of the power load for a certain period stored in the storage unit 40, and changes the power with time transition in the future (for example, one day) based on the history. Estimate and calculate the predicted load of the load and the predicted load of the thermal load that changes over time (for example, one day) (hereinafter abbreviated as “power load predicted demand” and “thermal load predicted demand”) The predicted power load demand and the predicted heat load demand are sequentially stored in the storage unit 40.

  The accumulation period of the past power load and heat load heat consumption history necessary for estimation of the predicted power load demand and the predicted heat load is a period in which the system can appropriately grasp the life cycle of each household. It is about several days to several months.

  As will be described in detail later, the operation planning unit 42 reduces the energy consumption of the cogeneration system 100 based on the predicted power load demand and the predicted heat load demanded by the prediction unit 41 for the PEFC 10 stored in advance in the storage unit 40. The start time and the scheduled stop time of the PEFC 10 are determined so that the energy consumption efficiency can be improved in each operation mode of the cogeneration system 100.

  Here, the storage unit 40 may be configured to store heat consumption histories of typical power loads and heat loads in advance when the cogeneration system 100 is installed at home.

  Various methods for estimating the power load predicted demand and the heat load predicted demand from the heat consumption history of the power load and the heat load have already been proposed, and detailed description thereof is omitted here.

  In the present embodiment, the prediction unit 41 and the operation planning unit 42 of the control system 104 have been described as being composed of a single microprocessor, but both may be configured by separate microprocessors, The microprocessor controls the overall operation (power generation operation and the like) of the cogeneration system 100 here, but the overall operation may be controlled by a separate computing unit.

  Next, an example of the operation of the control system 104 of the cogeneration system 100 based on the predicted heat load demand and the predicted power load demand will be described with reference to the drawings.

  FIG. 2 is a flowchart showing an operation example of the cogeneration system according to the present embodiment.

  Here, when the main switch of the cogeneration system 100 (for example, the power input switch of the remote control 43) is pressed, a plurality of menus are displayed on the display unit of the cogeneration system 100 (for example, the liquid crystal display unit of the remote control 43). . When the operation sequence of the cogeneration system 100 shown in FIG. 2 is selected by an appropriate operation of the input operation unit of the remote controller 43, the control program stored in advance in the storage unit 40 of the control system 104 is stored in the operation planning unit 42. The control program executes the processing shown in FIG. 2 while controlling the cogeneration system 100.

  Of course, the cogeneration system 100 may be designed so that the operation sequence can be automatically performed by operating the main switch. In executing this operation sequence as follows, an input instruction to the user is appropriately displayed as a message on the display unit.

  First, the operation planning unit 42 of the control system 104 acquires the predicted power load demand and the predicted heat load for a certain period (for example, one day) stored in the storage unit 40 (step S1).

  The predicted power load demand and the predicted heat load demand are predicted demands based on typical power and heat load heat consumption history stored in the storage unit 40 when the cogeneration system 100 is installed in each home. The predicted demand based on the heat consumption history of the power load and the heat load modified by the prediction unit 41 with the progress of the operation of the cogeneration system 100 so as to match the life cycle of each household may be used.

  Next, the operation planning unit 42 provisionally sets one of a number of combinations of the start time and stop time of the PEFC 10 as the temporary start time and stop time of the PEFC 10 (step S2).

  Subsequently, the operation planning unit 42 uses the PEFC 10 start time and stop time temporarily set in step S2 and the power load predicted demand and heat load predicted demand for a certain period (for example, one day) acquired from the storage unit 40. On the basis of this, the power generation amount generated by the PFEC 10 and the recovered heat amount recovered from the PEFC 10 to the hot water storage tank 22a during the operation period when it is assumed that the cogeneration system is operated during the temporarily set start time and stop time ( The total amount of hot water corresponding to this heat (hereinafter referred to as “hot water tank recovery hot water amount”) is calculated, and the time transition of the hot water tank recovery hot water predicted during this calculation is stored in the storage unit 40. Then, based on the predicted thermal load demand obtained from the storage unit 40 and the predicted data of the temporal transition of the hot water tank recovery hot water volume, hot water is supplied to the thermal load so as to cover the predicted thermal load demand as long as hot water is in the hot water storage tank. Based on the assumption, the time transition of the hot water amount of the hot water storage tank 22a stored in the cogeneration system 100 (hereinafter referred to as "hot water tank hot water amount") is predicted, and this prediction data corresponds to a temporarily set combination of start time and stop time. Then, it is stored in the storage unit 40. And the operation plan part 42 calculates the consumption energy (B) of the cogeneration system 100 required for the production | generation of the total amount of the said electric power generation amount and hot water storage tank collection | recovery hot water amount during an operation period (step S3).

  This energy consumption (B) is a measure for reducing energy consumption in the home when the cogeneration system 100 is introduced into the home. When the cogeneration system 100 generates the power generation amount and the hot water collected in the hot water tank, The raw material energy required for the operation of the PEFC 10 (the raw material gas consumed by the operation of the PEFC 10 and the total energy such as the operating power of the PEFC 10).

  Next, the operation plan unit 42 uses the power generation amount of the PEFC 10 and the recovered heat amount from the PEFC 10 during the temporarily set operation period (between the start time and the stop time) predicted by the operation plan unit 42 in step S3. Energy consumption (A) is calculated (step S4).

  This energy consumption (A) is a standard for reducing energy consumption in the home when the cogeneration system 100 is introduced into the home. The power generation amount of the PEFC 10 predicted by the operation planning unit 42 and This refers to the total energy when it is assumed that all of the recovered heat is covered by the power and gas supplied from the existing infrastructure of the power company or gas company without relying on the cogeneration system 100.

  Next, the operation planning unit 42 calculates a value (A−B) obtained by subtracting the consumed energy (B) in step S3 from the consumed energy (A) in step S4, and uses this to calculate the energy consumption reduction amount of the cogeneration system 100. Accordingly, the numerical value (A−B) is stored in the storage unit 40 in association with the combination of the start time and the stop time temporarily set in Step S2 (Step S5).

  Here, the operation planning unit 42 determines whether or not the calculation of the energy consumption reduction amount (AB) is completed for all combinations of the start time and the stop time (step S6), and the energy consumption reduction amount (A If the calculation of -B) is not completed ("No" in step S6), the processes of step S2, step S3, step S4 and step S5 are repeated, and the calculation of the energy consumption reduction amount (AB) is completed. If ("Yes" in step S6), the process proceeds to the next determination step.

  Next, the operation planning unit 42 selects one of the “power consumption maximum reduction operation mode” and the “hot water supply mitigation operation mode” of the cogeneration system 100 under appropriate conditions (step S7). .

  For example, the operation planning unit 42 constantly monitors whether or not the user has received a transition instruction (remote control switch input) to the “hot water relaxation operation mode”. 42 may control the operation of the cogeneration system 100 to shift from the normal “maximum energy consumption reduction operation mode” to the “hot water alleviation operation mode”.

  When the operation plan unit 42 selects the “maximum energy consumption reduction operation mode” in step 7, the operation plan unit 42 associates the energy consumption reduction amount (AB) with the storage unit 40 in step S 5. The combination of the start time and the stop time at which the energy consumption reduction amount (A-B) is maximized is read out from the storage unit 40 and acquired from the combination of the plurality of start times and stop times stored in Based on the combination of the stop time and the stop time, the scheduled start time and the stop time are set for the PEFC 10 (step S8).

  Then, the operation planning unit 42 controls the operation of the cogeneration system 100 in accordance with the scheduled start time and scheduled stop time of the PEFC 10 set in step S8 (step S9).

  On the other hand, when the operation plan unit 42 selects the “hot water relieving operation mode” in step 7, the operation plan unit 42 is stored in the storage unit 40 in association with the hot water storage tank hot water amount in step S 3. A combination of the start time and the stop time at which the hot water storage tank water quantity does not become zero is read out from the storage unit 40 and acquired from among a plurality of combinations of the start time and the stop time (step S10).

  In particular, it is desirable that the amount of hot water stored in the hot water storage tank is not zero when the hot water supply demand for the day is completed, and it is desirable to secure an amount of hot water that can meet the unexpected hot water supply demand.For example, the amount of hot water that covers this unexpected hot water supply demand Assuming that the amount of hot water used in general households is the maximum amount of hot water stored in the hot water storage tank 22a (for example, about 200L (liter)), the amount of hot water from 1/3 (70L) to 1/4 (50L) Is done.

  Then, the operation planning unit 42 combines the start time and the stop time at which the energy consumption reduction amount (A-B) is maximized from the combination of the start time and the stop time acquired in Step S10 (the acquired start time and stop time). If there is only one time combination, the combination of the start time and the stop time is selected, and the combination of the start time and the stop time is set as the scheduled start time and the stop scheduled time for the PEFC 10 (step S11). .

  Then, the operation planning unit 42 controls the operation of the cogeneration system 100 according to the scheduled start time and scheduled stop time of the PEFC 10 set in step S11 (step S9).

  According to such a cogeneration system 100, in the “hot water alleviation operation mode” of the cogeneration system 100, the operation planning unit 42 of the control system 104 responds to a heat load demand due to unexpected hot water supply or the like, and the hot water storage tank 22a. The operation of the cogeneration system 100 can be controlled so as to improve hot water shortage.

  In addition, the cogeneration system 100 is excellent in convenience because the user can appropriately select the “hot water draining mode of operation” and the “maximum energy consumption reduction mode of operation” according to the life cycle by a remote control switch.

  Next, an example of the setting (change) of the scheduled start time and the scheduled stop time of the PEFC 10 in the “hot water relaxation operation mode” will be described with reference to the drawings.

  FIG. 3 and FIG. 4 schematically show an example of an operation plan (setting or changing the scheduled start time and the scheduled stop time for the day) of the PEFC of the cogeneration system in the hot water relaxation operation mode (24 hours). It is a figure. Here, “standby” refers to a state in which the PEFC 10 has stopped its operation while the control system 104 is operating.

  FIG. 3 shows a case where the predicted hot water supply demand in the morning (time: 7 o'clock) and night (time: 21:00) is assumed, and when the unexpected hot water supply demand occurs, FIG. 4 is a diagram showing an example in which both are changed, and FIG. 4 shows a case where a predicted hot water supply demand is assumed at night (time: 21:00) and only the expected start time of PEFC when an unexpected hot water supply demand occurs. It is the figure which showed the example which changes.

  The numbers corresponding to the horizontal axes of the three bar graphs in FIGS. 3 and 4 represent the time of day and night. For example, the number “0 (24)” in the drawings is the time at midnight (24:00). The number “12” is the time of noon. The operation of the next day of the cogeneration system 100 is assumed to return to the leftmost bar from the rightmost bar figure (hereinafter referred to as “bar”) in the bar graph and repeat the same operation as that day.

  Moreover, the vertical axis | shaft in a figure represents the amount of hot water in the hot water storage tank 22a. Accordingly, each bar represents increase / decrease in the amount of hot water (or the magnitude of the hot water supply demand to the hot water storage tank 22a), and the bar extending to the “+” side shown in the figure is the amount of hot water remaining in the hot water storage tank 22a (or hot water storage tank 22a). The number “0” on the vertical axis indicates the hot water out condition of the hot water storage tank 22a, and the bar extending to the “−” side indicates the amount of hot water in the hot water storage tank 22a. .

  That is, the 25 light gray bars in each of the bar graphs in FIGS. 3 and 4 indicate the remaining hot water amount (or insufficient hot water amount) in the hot water storage tank 22a every hour and day. However, the bar at the left end shows the amount of remaining hot water at the beginning recognized by the system as midnight (24:00), and the bar at the right end shows the amount of remaining hot water at the end recognized by the system as midnight (24:00). Show.

  Also, the two dark gray bars (one in FIG. 4) in the bar graph of FIG. 3 are the prediction units 41 of the control system 104 at the time 7:00 and the time 21:00 (time 21:00 in FIG. 4). Exemplifies the amount of hot water in daily hot water demand (within prediction) already predicted by.

  Furthermore, the bar shown with one diagonal line in each of the bar graphs in FIGS. 3B and 3C is generated due to an unexpected factor at time 5:00 (time 7:00 in FIG. 4). The amount of hot water for the hot water supply demand (unforeseen) is illustrated.

  For the sake of simplification of the description of FIGS. 3 and 4, here, for convenience, the scheduled start time of the PEFC 10 is limited to one time around noon, and the scheduled stop time of the PEFC 10 is set to one time around midnight (24:00). The PEFC 10 is assumed to be in a steady operation (that is, the amount of hot water supplied to the hot water storage tank 22a per hour by the PEFC 10 and the heat radiation from the tank during the operation of the PEFC 10 are constant).

  In the bar graphs of FIGS. 3A and 4A, setting examples of the scheduled start time and the scheduled stop time of the PEFC 10 in the hot water supply relaxation operation mode of the present embodiment are shown.

  According to these bar graphs, a larger amount of hot water than that required for daily hot water supply demand (within prediction) is stored in the hot water storage tank 22a while the PEFC 10 is on standby. For example, as shown in FIG. 3, even if the hot water supply demand within the prediction at 7:00 and 21 is covered by hot water in the hot water storage tank 22a, a predetermined amount of hot water remains in the hot water storage tank 22a.

  Therefore, as shown in the bar graphs of FIGS. 3 (b) and 4 (b), when an unexpected hot water supply demand occurs, it is compared with the hot water usage logic of the hot water storage tank as in the conventional fuel cell cogeneration system. The hot water shortage due to the unforeseen hot water supply demand can be compensated for at a certain level, and the increase in the hot water supply amount by the backup burner installed in the hot water supply facility can be suppressed.

  In addition, the bar graphs of FIG. 3C and FIG. 4C show the scheduled start time and scheduled stop time of the PEFC 10 in the hot water supply relaxation operation mode of this embodiment when an unexpected hot water supply demand occurs. An example of change (update example) is shown.

  The operation planning unit 42 of the control system 104 grasps the occurrence of unforeseen hot water supply demand and the amount of hot water due to the unforeseen hot water supply demand based on the detection information of the flow meter 22d, and calculates the daily hot water demand (within the prediction) ) To estimate the amount of hot water remaining after subtracting the amount of hot water remaining in the hot water storage tank 22a. Then, the operation planning unit 42 temporarily changes the scheduled start time (unarrived time) and / or scheduled stop time (unarrived time) of the PEFC 10 so as to cover this insufficient amount of hot water.

  More specifically, as understood from the comparison between the bar graph of FIG. 3A and the bar graph of FIG. 3C, the operation planning unit 42 has grasped the unexpected hot water supply demand and the insufficient amount of hot water. Both the scheduled start time and the scheduled stop time of the PEFC 10 are changed so that the next scheduled start time is advanced and the next scheduled stop time is delayed to cover the above-mentioned insufficient amount of hot water.

  Similarly, as understood from the comparison between the bar graph diagram of FIG. 4A and the bar graph diagram of FIG. 4C, the operation planning unit 42 grasps the unexpected hot water supply demand generation and the insufficient hot water amount. Only the scheduled start time of the PEFC 10 is changed so that the next scheduled start time is advanced and the above-mentioned shortage of hot water can be completely covered.

  The operation plan unit 42 recognizes that the unexpected hot water supply demand is irregular until it gets tired, and on the day after the shortage of hot water is covered, the operation of the PEFC 10 changed based on the unexpected hot water supply demand is started. The scheduled time and / or scheduled shutdown time is changed to the scheduled time of the PEFC 10 when there is no unexpected hot water supply demand (that is, the scheduled startup time and scheduled shutdown time shown in FIGS. 3A and 4A). return.

  However, if unforeseen hot water supply demands occur on the same day (for example, for a week) and the same amount at the same time, the operation plan unit 42 recognizes that the unforeseen hot water demand is constant, This hot water demand may be incorporated into the predicted hot water demand. For example, if the unexpected hot water supply demand at the time 7:00 shown in FIG. 4B or FIG. 4C is continuously generated for several days, the operation planning unit 42 determines the demand for hot water supply in the morning (time 7:00). 3 is determined as a constant demand, and as shown in FIG. 3A, the scheduled start time and the scheduled stop time of the PEFC 10 are reset (update setting) so as to assume the hot water supply demand in the morning and evening. May be.

  According to the setting and changing operation of the scheduled start time and the scheduled stop time of the PEFC 10 in the hot water cut off operation mode of the present embodiment as described above, the burden on the backup burner built in the hot water supply facility is reduced, which is efficiently unexpected. Suitable for supplying hot water supply.

[Modification 1]
In the present embodiment, paying attention to the energy consumption reduction amount (AB) of the PEFC 10, the operation planning unit 42 sets the operation plan of the cogeneration system 100 so as to maximize such energy consumption reduction amount. An example was given. However, the operation plan of the cogeneration system 100 may be set not only for the energy consumption reduction amount but also for example, paying attention to the cost reduction amount and the carbon dioxide emission reduction amount of the PEFC 10. That is, the operation planning unit 42 sets the scheduled start time and the scheduled stop time for the PEFC 10 so as to maximize at least one of the energy reduction amount, the cost reduction amount, and the carbon dioxide emission reduction amount of the PEFC 10. May be.

  It should be noted that these cost reduction amount and carbon dioxide emission reduction amount can be calculated using data necessary for deriving the energy consumption (A) and (B) already described.

  For example, the operating cost of the PEFC 10 can be derived by multiplying the raw material gas and electric power necessary for the operation of the PEFC 10 by the cost per unit amount. Further, the carbon dioxide emission amount per unit raw material gas amount can be easily derived from the carbon (C) ratio in the raw material gas. For the amount of carbon dioxide emission per unit energy of electric power, data already published by the electric power company may be used.

[Modification 2]
In addition to the “maximum energy consumption reduction operation mode” and “hot water drain mitigation operation mode” described in this embodiment, in preparation for emergencies (especially during nighttime disasters), the cogeneration system is on standby (especially at night). An emergency response operation mode that can ensure the maximum amount of hot water (maximum heat storage amount) can be added to the hot water storage tank (at the time of standby), and these three operation modes can be selected as an operation mode selector such as a remote control switch. A cogeneration system may be constructed so that the user can select appropriately. This is convenient because the user can appropriately select an operation mode suitable for the life cycle by the remote control switch.

[Modification 3]
In the present embodiment, the setting of the scheduled start time and the scheduled stop time by the operation planning unit 42 is based on several calculations based on the predicted power load demand and the predicted heat load stored in the storage unit 42 as described above. And finally through the predictions are set. Since the predicted power load demand and the predicted heat load generally vary depending on the season, day of the week, etc., the scheduled start time and scheduled stop time set by the operation planning unit 42 also vary accordingly. Therefore, the scheduled start time and the scheduled stop time according to the time are patterned and stored in the storage unit 40, and the operation plan unit 42 selects an optimum pattern on the day of operation from the storage unit 40, and the planned start time and stop plan A time may be set.

  According to the cogeneration system of the present invention, it is possible to appropriately cope with the heat load demand due to unexpected hot water supply or the like. For example, the present system is useful for a household fuel cell cogeneration system.

It is the block diagram which showed the example of a structure of the cogeneration system by embodiment of this invention. It is the flowchart which showed the operation example of the cogeneration system by this Embodiment. It is the figure which showed typically an example of the operation plan of PEFC of the cogeneration system by a hot water relaxation operation mode. It is the figure which showed typically the other example of the operation plan of PEFC of the cogeneration system by a hot water relaxation operation mode.

Explanation of symbols

10 PEFC
11 Fuel Supply Unit 12 Air Supply Unit 21a Cooling Water Circulation Channel 21b Cooling Water Pump 21c Heat Recovery Water Circulation Channel 21d Heat Recovery Water Pump 22a Hot Water Storage Tank 22b Hot Water Supply Pipe 22c Hot Water Supply Pipe 22d Flow Meter 22e Outlet 22f Inlet 23 Heat Exchanger 30 Inverter 31 Commercial Power Network 32 Wattmeter 33 Commercial Power Supply 40 Storage Unit 41 Prediction Unit 42 Operation Planning Unit 43 Remote Control 100 Cogeneration System 101 Combined Electric Heat System 102 Heat Utilization System 103 Electric Power System 104 Control System

Claims (1)

A cogeneration unit that generates power and heat;
A regenerator for storing heat generated by the cogeneration unit;
A memory for storing a predicted heat load demand of a heat load supplied with heat from the regenerator, a predicted recovered heat amount from the combined heat and power supply to the regenerator, and a predicted power generation amount of the combined heat and power supply device And
An operation mode selector for selecting either the first operation mode or the second operation mode;
A controller, and
The controller, when the first operation mode is selected by the operation mode selector,
A starting time at which an amount of heat exceeding a value necessary to cover the predicted thermal load demand based on the predicted thermal load demand and the predicted recovered heat amount acquired from the storage unit is stored in the regenerator; Set the combination of stop time as the scheduled start time and the scheduled stop time,
When the second operation mode is selected by the operation mode selector, based on the predicted power generation amount and the predicted recovered heat amount acquired from the storage device, the energy consumption reduction amount and cost of the combined heat and power supply A combination of start time and stop time that maximizes at least one of the reduction amount and the carbon dioxide emission reduction amount is set as the planned start time and the planned stop time ,
The operation mode selector is a cogeneration system that is a remote control switch operated by a user .

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